Pin clamps which use movable locating pins to engage and grip a workpiece are known. Characteristically, such pin clamps employ a reciprocally or rectilinearly moving locating pin with a movable finger or fingers positioned therein. The locating pin extends to engage a hole in a workpiece such as a metal sheet. The locating pin then retracts causing the finger or fingers within the locating pin to extend and hold the workpiece against the clamp body.
Conventional pin clamps, however, do not include devices that move the locating pin to a clamping position without extending the fingers, or can hold the locating pin in a particular position absent actuation force. Because the possibility exists that material from a clamped workpiece may get stuck on the clamp, being able to move the locating pin without having the finger or fingers extend may be useful at dislodging the material. It may also be useful for certain pin clamps to be able to hold the locating pin in a particular position even under an unexpected loss of pressure.
Accordingly, an illustrative embodiment of the present disclosure provides a pin clamp assembly which comprises first, second and third pins, a finger and stripper assembly. The first pin moves in response to an actuation. At least one finger is positioned adjacent the first pin, and is movable between clamped and unclamped positions. The second pin is located adjacent the first pin and is in operable communication with the finger. The stripper assembly comprises the third pin that is selectively engagable with the second pin, and an actuator that moves the third pin. The first activation of the actuator moves the third pin causing it to engage the second pin causing it to move the finger to the clamped position. The second actuation of the actuator moves the third pin causing it to disengage from the second pin causing it to not move the finger to the clamped position.
In the above and other illustrative embodiments, the pin clamp assembly may further comprise: actuation of the first pin to move the second pin; disengagement between the second and third pins to maintain the finger in the unclamped position; the actuator of stripper assembly being pneumatic powered; the first pin having a cavity disposed therein configured to receive at least a portion of the second pin; the second pin having a cam pathway disposed therein configured to receive a portion of the third pin such that movement of the second pin is limited by the shape of the cam pathway and the portion of the third pin following the cam pathway as the second pin moves; engagement between the cam pathway and the portion of the third pin, and movement of the second pin, moves the finger to the clamped position; second actuation of the actuator causes the portion of the third pin to be removed from the cam pathway so that movement of the second pin is no longer limited by the shape of the cam pathway and the finger does not move to the clamped position; and disengagement of the third pin from the cam pathway allows the finger to be located in the unclamped position even if the finger would other wise be moved to the clamped position upon movement of the locating pin.
Another illustrative embodiment of the present disclosure provides a pin clamp assembly which comprises a body, a locating pin, a twist pin, and a stripper assembly. The body defines an internal cavity and an opening from the cavity to the exterior of the body. The locating pin is at least partially disposed in the cavity and extends out of the opening to a distal end. At least a portion of the twist pin is located in the locating pin. Upon actuation of the pin clamp assembly, the twist pin and the locating pin moves. The stripper assembly comprises a stripper pin which is at least partially disposed in the body and which selectively engages and disengages the twist pin to cause or inhibit particular movement of the twist pin.
In the above and other illustrative embodiments, the pin clamp assembly may further comprise: the stripper assembly further comprising an actuator that moves the stripper pin to cause the stripper pin to selectively engage and disengage the twist pin; the actuator being a pneumatic piston assembly; the pneumatic piston assembly extending and retracting the stripper pin to engage and disengage the twist pin; the pin clamp assembly further comprising at least one finger supported by the locating pin exterior of the body and configured to extend and retract upon the particular movement of the twist pin; actuation of the pin clamp assembly and selective engagement of the twist pin by the stripper pin causes rotational movement of the twist pin to extend the finger; actuation of the pin clamp assembly and selective disengagement of the twist pin by the stripper pin does not cause the rotational movement of the twist pin which does not extend the finger; the pin clamp assembly further comprising a plurality of fingers supported by the locating pin exterior of the body and configured to extend and retract upon the rotational movement of the twist pin.
Another illustrative embodiment of the present disclosure provides a pin clamp assembly which comprises a locating pin that is movable with respect to a body, wherein retraction of the locating pin with respect to the body causes extension of at least one finger configured to hold a workpiece adjacent the body, and a stripper assembly for selectively preventing the finger from holding a workpiece upon retraction of the locating pin. In the above and other illustrative embodiments, the pin clamp assembly may further comprise the stripper assembly comprising an actuator for selective extension and retraction of the finger independent of the movement of the locating pin.
Another illustrative embodiment of the present disclosure provides a method of operating a pin clamp assembly that comprises a locating pin that moves rectilinearly, holds a workpiece by actuating at least one finger located adjacent the locating pin. The method comprises the steps of: providing a stripper assembly that selectively prevents the finger from actuating; actuating a member extending from the stripper assembly which causes that member to disengage from a portion of the pin clamp assembly that moves the finger; actuating the locating pin to move the same in a first direction; and moving the locating pin in the first direction without actuating the finger.
In the above and other illustrative embodiments, the method of operating a pin clamp assembly further comprises the steps of: actuating the member which causes it to engage the portion of the pin clamp assembly that moves the finger; actuating the locating pin to move it in the first direction; moving the locating pin in the first direction; and actuating the finger to move and engage a workpiece. The method may further comprise the steps of: actuating the member which causes it to engage the portion of the pin clamp assembly that moves the finger; actuating the locating pin to move it in a second direction; positioning the locating pin adjacent the workpiece; actuating the locating pin again; moving the locating pin in the first direction; actuating the finger by the engagement of the portion of the pin clamp assembly that moves the finger and the finger; and engaging the workpiece by the finger.
Additional features and advantages of the pin clamp assembly and accessories will become apparent to those skilled in the art upon consideration of the following detailed description of the illustrated embodiment exemplifying the best mode of carrying out the pin clamp assembly and accessories as presently perceived.
Corresponding reference characters indicate corresponding parts throughout the several views. The exemplification set out herein illustrates embodiments of the pin clamp assembly and accessories, and such exemplification is not to be construed as limiting the scope of the pin clamp assembly and accessories in any manner.